1. Field of the Invention
The invention relates to a method for transferring a feed strip of a material web, in particular a paper or cardboard web, onto a winding device for winding the material web onto a spool, in which the material web or the feed strip is led over a carrier drum and a winding nip is formed between the carrier drum and the spool. It further relates to a winding apparatus for winding a material web, in particular a paper or board web, onto a spool, in which the material web is led over a carrier drum and a winding nip is formed between the carrier drum and the spool.
2. Discussion of Background Information
Winding devices of the aforementioned type are known, for example from the documents DE 198 22 261 A1, DE 198 52 257 A1, DE 199 39 506 A1, WO 98/52858 and EP 0 483 092 B1.
The previous general sequence of a corresponding feed operation in a papermaking machine comprises the following steps:                At the end of the drying section, that is to say on the last drying cylinder, the paper web is run at full width into the pulper.        A strip is cut, for example by means of a tip cutter.        The strip is taken off the last drying cylinder and transferred to a winding device or reel-up by means of a rope guide, vacuum tapes, air plate and/or the like.        The strip is raised up and pulled tight.        The strip is run to the full web width.        
In this case, the clamping point used for the strip is the winding nip or nip formed between a carrier drum and an empty spool.
The line force in the nip is produced by pressing, the empty spool being pressed appropriately against the carrier drum or the carrier drum being pressed appropriately against the empty spool.
Pressing the empty spool against the carrier drum or the carrier drum against the empty spool is usually carried out by means of two hydraulic cylinders, one of which is provided on the operator side and one on the drive side and which are acted on with the same pressure. The result of the uniform pressing or identical pressing force on the operator side and the drive side is a nip which is closed over its entire width.
Moreover, in general a feed position has hitherto been provided on the rail or between the changeover position and the horizontal position on the rail. The distribution of the line force has hitherto generally depended on the following variables:                level of the pressing force        changeover position (changeover angle)        rigidity of carrier drum and spool        design of the surfaces of carrier drum and spool (steel, rubber covering, hardness)        diameter of carrier drum and spool.        
In this case, the distribution of the line force or pressure with respect to the center of the machine has hitherto always been symmetrical.
During the feeding or transfer of the feed strip, problems can occur in particular in the case of a rubber-covered carrier drum that has shrunk. For example, a carrier drum that has shrunk signifies a reduction in diameter. The nip force or pressure is lower at the relevant point, in the extreme case it being possible for the nip even to be open at the relevant point, that is to say no longer fully closed. The transfer strip can then no longer be gripped.